Chemical manufacture



Patented June 26, 1945 UNITED STATES PATENT OFFICE CHEMICAL MANUFACTURE Willard L. Finley, Washington, D. C., assignor to Sinclair Refining Company, New York, N. Y.,

a corporation of Maine No Drawing. Original application September 6,

1941, Serial No. 409,841. Divided and this application March 24, 1943, Serial No, 480,375

1 Claim. (Cl. 260-474) follows:

-OCaO- COOR R000 where R represents the l-methyl heptyl radical or, in other words, the alkyl radical of capryl alcohol. I

The calcium capryl salicylate of my present invention may be prepared by reacting thecapryl ester of salicylic acid with hydrated lime suspended in a volatile inert solvent such as benzene, naphtha, toluene or the like, at an elevated temperature. The reaction by which the neutral calcium salt of the ester is formed may be graphically represented as follows:

-COOR ROOO For example, the calcium capryl salicylate in substantially pure form may be prepared by the direct reaction of capryl salicylate with hydrated lime in the presence of a volatile solvent as follows: 60.3 grams of Ca(OH)z of 92% purity, i. e. 0.75 mole, is suspended in 1200 grams of naphtha by rapid stirring. 375 grams (1.5 moles) of capryl salicylate and 18 c. c. of water are then slowly added. The mixture is held at a temperature of about 160 to 180 F. for about 1 hour and finally heated to about 280 F. to drive off moisture. Duringthis mixing and heating operation, the mixture is rapidly stirred. After the moisture has been driven oil, the solution is filtered and finally the solvent is removed from the filtrate by topping to a temperature of 250 F'., at

an absolute pressure of 1 millimeter of mercury. By this procedure, the calcium capryl salicylate has been obtained as a viscous liquid residue containing 7.60% calcium as compared with the theoretical value of 7.43% calcium for the neutral calcium salt. V

The product of my present invention may also be prepared by double-decomposition or methasis by first reacting the ester with sodium hydroxide to form the corresponding sodium salt and react ing the resulting sodium salt with calcium chloride as indicated by thefollowing graphical representation of the reaction:

-ONa

+ NaOH m0 CO0R 000R 0Na 2 CaCli -v COOR For example, the calcium capryl salicylate may be prepared by methasis as follows: 8.4 grams (.21

mole) of caustic soda of 76% NazQ is dissolved in,

25 c. c. of water. This solution is then slowly added to a rapidly stirred solution of c; c. ethyl alcohol and 50 grams (0.20 mole) of capryl salicylate. After a few minutes of rapid stirring, 100 c. c. of benzol and finally 22.2 grams (0.20 mole) of calcium chloride in 40 c. c. of water are slowly added and the stirring continued for 5 minutes. After the cessation of stirring, an upper layer comprising a benzene solution of the calcium capryl salicylate is formed. This upper layer is then separated, filtered and topped under vacuum as indicated in Example I, for the removal of the solvent. By this procedure, a 51 gram yield of the calcium capryl salicylate has been obtained as a viscous liquid containing 7.67% calcium.

As graphically indicated above, 1 mole of sodium hydroxide is required to react with each mole of the ester to form 1 mole of the sodium salt, and 2 moles of the resulting sodium salt are required to react with each mole of the calcium chloride to form the neutral calcium salt of the ester. However, in carrying out the reaction, it is usually desirable to use an excess of sodium hydroxide and of the calcium chloride such as thealkyl ester.

foregoing methods, contains slightly more than the theoretical percentage of calciumfortheneutral salt. While I cannot statetwith certainty the reason for the presenceof this excess cal cium, it is my present belief that it is due to the presence of a small amount of basic calcium capryl salicylate formed during: the reaction. This basic salt may be graphically representedas COOR where R represents the alkylradical of capryl alcohol and wherein only one of the hydroxy radicals of the calcium hydroxide-hasreacted with -In no instance has the excess calciumin the product been in excess-of50% and, in most instances, it has been found to-vary between 5 and Insome instances the presence of such an excess of combined calcium inthe product has been found desirable. For example, where usedas .an additionagent in the compounding 'of' lubricating oils, I have found the calcium capryl salicylate ofmytpresent invention, which-contains-a considerable excess of combined calcium, or be superior in some respects to those which contain more nearly the theoretical-amount forthe neutral calcium salt. 1

The amount of combined calcium present in the product in excess-of the theoretical amount for neutral calcium caprylsalioylate, and which I believe to be due to the presence of the basic calcium capryl=, alicylate, may be. increased by using a greater excess of lime in the process first -..described,-for example equal molar proportions of lime and caprylsalicylate may berused I The product of mypresent-invention is soluble tmaconsiderableextent-in mineral oil and has been found to bee particularly valuable addend in the-compounding of lubricatingioils. Various addition agents. have been. used for improving .cer-

.taln properties of-lubricating oil. Some. have been found to stabilize the oilagainst oxidation or sludging. Other 7 addition agents have been .found to inhibit .corrosion .of the alloy orothe'r metal bearings andparts of the machine. to be lubricated, particularlyinternal combustion en'- gines-where operating conditions are especially severe. Otheraddition agents have been found to increasethe fllm strength of the lubricating oil.

Still further addition agents have been found effectivelyto preventexcessiv accumulation ordecomposition products on the pistons and rings of .intemal combustion enginesand in, altering the nature of such depositsas are formedthereon.

.have been found to interfere with the proper functioning of one another.

I have discovered that thecalcium capryl salicylate of my presentinvention is sufllciently soluble inlubricatingoil to permit the solution of effectiveamountsin the oil and that, when used in small amounts as addition agents in the compounding of lubricating oil, it functions asa strong anti-oxidant, efiectively inhibiting for prolonged induction periods the rate of oxygen absorption at elevated temperatures and thu limit ing any corrosive tendency of the lubricating oil composition With respect to bearing metals. has also been found to render, deposits of sludge and fcarbon within the engine soft and friable rather than hard and coherent and to act as a solvent for sludge formed, thus disintegrating and removing any deposits of sludge and carbon as are incident to normal engine operation.

The use of various calcium alkyl salicylates, including calcium capryl salicylates, as addition agents in lubricating oil compounds is described and claimed in my co-pending applications Serial No. 368,992, filed December7, 1940, Serial No. 407,002, filed August 15, 1941, and Serial No. 417,471, filed November 1, 1941.

Where the product of my present invention is to be used as anaddition agentin the compounding of lubricating oils, it has Withadvantage been 4 prepared. bydirectreaction between capryl salicylate and'hydratedlime in an oil medium, for example, as follows: 2575 grams of S. A.; E. 30 lubricating oil wasplaced in a-Z-gallon reactor equipped with a heater and aniefficient stirring .mechanism. 1 222 grams (3' moles) of calcium hydroxide was evenly dispersed in the oil by rapid .stirringand then 750 grams '(3 moles) of capryl salicylate and 37.5 rams of water were slowly .added and stirred into themixture. Stirring was continued and the mixture maintained at atemperature of about -180 F. for 1 hour. Thereafter, the temperature was slowly raised over a period of 1 hour to 280 F. to drive off moisture added and formed in the reaction. The resulting hot calcium capryl salicylate solution is then filtered to remove excess lime. Oil filtrates prepared by this procedure were found to contain 2.25% calcium as calcium capryl salicylate which, consistent with the examples previously given, exceeds the theoretical. amount for the neutral salt, i. e. 1.79% calcium for a 24% solution. This excess is believed to bedue to the presence-'of basic calcium. capryl salicylate, as, previously noted.

I claim: e

As a composition of matter, the .calcium salt of l-methyl heptyl salicylate.

WILLARD L. FINLEY. 

